In recent years, demands for high-resolution and high-quality videos have increased more and more in various fields of applications. With improvement in resolution and quality of a video, an amount of data of the video also increases.
With the increase in the amount of data, apparatuses having a variety of performance and networks having various environments have been developed.
With the development of the apparatuses having a variety of performance and the networks having various environments, the same contents can be used with a variety of quality.
Specifically, since video quality which can be supported by terminals diversifies and the constructed network environments diversify, videos with general quality can be used in some environments but videos with higher quality can be used in other environments.
For example, a user having purchased video contents with a mobile terminal can enjoy the video contents with a larger screen and a higher resolution using a large-screen display at his or her home.
With recent broadcast services with a high definition (HD) resolution, users have got accustomed to high-resolution and high-quality videos and service providers and users have been interested in ultra-high definition (UHD) services with a resolution of four or more times that of HDTV as well as HDTV.
Therefore, in order to provide video services requested by users in various environments depending on the quality, it is possible to provide scalability to video quality such as image quality of a video, a resolution of a video, a size of a video, and a frame rate of a video on the basis of high-efficiency encoding/decoding methods for high-capacity videos.